Control contentPlaceHolder1txtName of type TextBox must be placed inside a form tag with runat

http://www.aspsnippets.com/Articles/Contact-Us-Form-with-Rich-TextBox-in-ASP.Net.aspx

i have used above code but is giving error

Control 'contentPlaceHolder1_txtName' of type 'TextBox' must be placed inside a form tag with runat=server.

wt should i do

i have copied the above code as it is .